General  Circulation 
of  the 

Atmosphere 

ONE  OF  A SERIES  OF 
PAMPHLETS  ON 

Important  Topics  in  Geography 


By  DOUGLAS  C.  RIDGLEY 
Professor  of  Geography , Illinois  State  Normal  University 
Normal , Illinois 


SiOLQQY 


published  by 

Mcknight  & Mcknight 

Normal,  Illinois 


9 


5 S\(  S\ 

' ' or/U: 

NOTE 

This  pamphlet  is  the  first  of  a series  contem- 
plated by  the  writer  dealing  with  Important  Topics 
in  Geography  which  can  not  receive  adequate  treat- 
ment in  the  usual  text  books  because  of  the  limited 
space  which  must  necessarily  be  given  to  them. 
The  topic  treated  in  this  pamphlet — General  Circu- 
lation of  the  Atmosphere — is  fundamental  to  any 
causal  study  of  the  geography  of  the  world  so  far 
as  it  deals  with  the  amount  and  distribution  of 
rainfall  and  its  consequences;  namely,  vegetation, 
animal  life,  distribution  of  population,  etc. 

To  know  the  wind  belts  of  the  earth  as  to  loca- 
tion and  direction  of  air  movement  is  to  have  the 
key  by  which  to  interpret  the  rainfall  of  a region. 
To  know  the  temperature  and  rainfall  of  a region 
enables  the  student  to  interpret  its  vegetation.  To 
know  the  natural  vegetation  of  a region  gives  a 
basis  for  the  study  of  the  settlement  and  industrial 
development  of  a country. 

Other  pamphlets  under  consideration  at  the  pres- 
ent time  are:  Rainfall  of  the  Earth;  Vegetation 
Zones  of  the  earth ; and  Population  of  the  Earth. 

These  are  intended  for  use  in  the  geography 
classes  of  the  upper  grades  and  in  the  physical  and 
commercial  geography  classes  of  the  high  school  as 
supplementary  to  the  regular  text  book  treatment 
of  the  same  topics.  This  pamphlet  on  General 
Circulation  of  the  Atmosphere  covers  fully  the  topic 
as  outlined  in  the  Illinois  State  Course  of  Study. 

Douglas  C.  Ridgley. 

Department  of  Geography,  1 \ 

Illinois  State  Normal  University,  ' ^ *. 

Normal,  Illinois. 

° 4 ''048 


Copyright  1910 
By  Douglas  C.  Ridgley 


GENERAL  CIRCULATION  OF  THE 
ATMOSPHERE 


Introduction.  To  understand  the  geography  of 
the  earth  we  need  to  know  much  about  the  surface 
of  the  land,  the  temperature,  rainfall,  vegetation, 
animal  life,  and  the  people  of  the  various  regions 
of  the  earth.  We  also  need  to  know  the  reasons  for 
these  things  as  we  find  them  in  different  continents 
or  countries.  We  all  know  that  the  air,  or  atmos- 
phere, is  almost  always  in  motion.  When  the  air 
is  not  in  motion  we  say  that  it  is  calm.  Moving  air 
is  called  wind. 

The  winds  may  be  light,  moderate,  brisk,  or  high. 
The  regions  of  the  world  having  calm  air  at  any 
time  are  very  small  in  comparison  to  the  regions 
having  winds. 

The  general  circulation  of  the  atmosphere  in- 
cludes the  usual  condition  of  the  air  as  found  in  large 
areas  of  calms  or  winds  on  the  earth’s  surface.  Its 
study  will  teach  us  the  location  and  extent  of  these 
regions  of  calms  and  winds  in  general,  and  their 
shifting  north  and  south  with  the  change  of  seasons. 
It  will  also  give  us  some  understanding  of  the  rea- 
sons for  rainfall  and  for  the  distribution  of  plants, 
animals,  and  people  in  the  various  regions  of  the 
earth. 

Some  Facts  to  be  Remembered.  There  are  many 
important  things  about  the  atmosphere  which  have 
been  learned  by  the  careful  study  of  scholars,  and 
which  boys  and  girls  may  know  and  use  in  their  study 


4 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


of  geography,  and  in  the  observation  of  many  things 
in  their  daily  experiences.  Some  of  them  are  the 
following : 

1.  Air  has  weight.  Fill  a glass  jar,  or  a bottle, 
with  water.  Invert  it  with  the  open  end  just  under 
the  water  in  a pan  or  pail.  Does  the  water  run  out 
of  the  jar  or  bottle?  Why?  Try  with  the  longest  glass 
vessel  or  tube  you  can  get.  At  sea  level  air  pressure 
is  about  15  pounds  to  the  square  inch.  This  means 
that  a column  of  air  one  inch  square  and  extending 
to  the  top  of  the  atmosphere  (more  than  100  miles) 
weighs  15  pounds. 

The  air  in  a box  or  a tank  10  ft.  by  10  ft.  by  5 ft. 
at  freezing  temperature  weighs  about  38  pounds. 

2.  Air,  when  warmed,  expands;  when  cooled, 
contracts.  This  means  that  as  air  grows  warmer, 
the  same  air  occupies  more  space  than  before  it  was 
warmed.  If  it  grows  cooler,  it  occupies  less  space 
than  before  it  was  cooled. 

Think  of  a space  10  ft.  by  10  ft.  by  5 ft.  filled 
with  air  at  a temperature  of  32  degrees,  freezing 
temperature.  You  have  500  cu.  ft.  of  air.  If  this 
air  is  warmed  1 degree,  to  33  degrees,  it  will  expand 
and  occupy  501  cu.  ft.  of  space.  If  cooled  1 degree, 
to  31  degrees,  it  will  contract,  and  occupy  499  cu.  ft. 
of  space.  If  warmed  to  52  degrees  it  will  occupy 
520  cu.  ft.,  if  cooled  to  12  degrees  it  will  occupy  480 
cu.  ft. 

3.  Warm  air  is  lighter  than  cold  air,  other  con- 
ditions being  the  same.  The  500  cu.  ft.  of  air  at 
freezing  weighs  about'  38  pounds.  Warmed  to  52  de- 


GENERAL  CIRCULATION  OR  THE  ATMOSPHERE  5 


grees,  it  occupies  520  cu.  ft.,  but  still  weighs  only  38 
pounds  as  before;  500  cu.  ft.  of  the  warmer  air 
weighs  less  than  3 6%  pounds. 

Cold  air  on  a mountain  top  is  lighter  than  the 
warmer  air  at  the  base  of  the  mountain  because  the 
conditions  are  not  the  same.  The  air  at  the  base  of 
the  mountain  is  under  greater  pressure  than  the  air 
higher  up. 

4.  Warm  air  can  hold  more  water  vapor,  or 
moisture,  than  cold  air.  At  32  degrees  air  cannot 
hold  very  much  water  vapor,  at  50  degrees  it  can 
hold  about  twice  as  much  as  at  32  degrees;  at  70 
degrees  nearly  four  times  as  much  as  at  32  degrees ; 
and  at  90  degrees  nearly  eight  times  as  much  as  at 
32  degrees. 

5.  Moist  air  is  lighter  than  dry  air,  other  con- 
ditions being  the  same.  We  usually  speak  of  the 
“heavy”  air  of  a warm,  damp,  cloudy,  sultry  day; 
and  of  the  “light”  air  of  a cool,  clear,  dry  day.  This 
is  because  of  our  feeling,  not  because  of  the  weight 
of  the  air.  The  barometer,  which  is  an  instrument 
for  measuring  the  pressure  of  the  air,  shows  clearly 
that  the  pressure  is  greater,  therefore,  the  air 
heavier,  on  clear,  dry  days,  than  on  damp,  rainy 
days.  Find  a description  and  a picture  of  a barome- 
ter in  your  school  geography  or  in  a physical  geog- 
raphy, and  learn  how  it  records  the  pressure  or 
weight  of  the  air.  If  you  have  a barometer  at 
school,  watch  it  each  day  for  a month  or  more  and 
learn  for  yourself  what  it  tells  about  air  pressure 
on  different  kinds  of  days. 


6 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


Circulation  of  Air  on  a Small  Scale.  Hold  a 
smoking  match  below  the  burner  of  a lighted  lamp. 
The  smoke  can  be  seen  passing  upward  through  the 
chimney.  Hold  the  hand  above  the  chimney  of  the 
lighted  lamp.  The  current  of  warm  air  moving 
upward  can  he  plainly  felt.  The  air  around  the 
flame  of  the  lamp  is  heated;  it  expands;  it  becomes 
lighter ; the  cool  air  around  the  lamp  is  heavier  than 
the  warm  air  inside  the  lamp  chimney;  it  enters 
through  the  openings  on  the  under  side  of  the 
burner,  and  pushes  the  warmer,  lighter  air  upward 
through  the  chimney.  The  air  which  entered 
through  the  burner  is  now  heated,  and  pushed  up- 
ward by  additional  air  entering,  and  so  the  move- 
ment of  the  air  about  the  lamp  goes  on  as  long  as  the 
flame  continues  to  burn. 

The  smoke,  rising  from  the  chimney  of  a house, 
tells  the  same  story  of  the  air  movement  as  the  lamp. 
State  it.  The  leaping  flames  and  flying  cinders  from 
a bonfire  tell  of  the  warm,  expanded  air  near  the 
fire  being  pushed  rapidly  upward  by  the  colder, 
heavier  air  moving  inward  near  the  ground.  The 
warm,  quivering  air  seen  over  a hot  stove  on  a 
winter  day  illustrates  the  same  thing  as  the  lamp  or 
house  chimney.  The  air  near  the  stove  is  heated 
rapidly  by  the  hot  stove.  It  expands,  grows  lighter, 
and  the  colder,  heavier  air  on  all  sides  pushes  the 
hot  air  rapidly  upward.  It  carries  heat  upward  and 
outward  to  all  parts  of  the  room. 

Let  us  suppose  that  our  school  room  is  heated 
by  a steam  pipe  running  entirely  across  the  middle 


GENERAL  CIRCULATION  OP  THE  ATMOSPHERE  7 


of  the  room  from  east  to  west  near  the  floor.  Let 
us  have  the  north  and  south  windows  open  a few 
inches  at  the  top.  After  a cold  night,  all  parts  of 
the  room  have  been  cooled  to  the  same  temperature 
and  there  is  no  circulation  of  the  air. 

When  the  hot  steam  passes  into  the  pipe  in  the 
morning  let  us  see  what  takes  place. 

1.  The  heat  of  the  steam  passes  through  the 
solid  iron.  Heat  passes  through  a solid  body  in 
this  way  by  the  process  of  conduction. 

2.  The  heat  passes  from  the  pipe  into  the  air 
surrounding  it.  The  air  in  contact  with  the  pipe  is 
heated  by  conduction.  The  heat  radiates  or  passes 
out  into  the  air  in  all  directions,  and  we  say  that  the 
air  is  heated  by  radiation  also. 

3.  As  the  air  near  the  pipe  is  warmed,  it  ex- 
pands and  grows  lighter.  The  colder,  heavier  air 
on  the  north  and  south  sides  of  the  pipe  pushes 
against  the  warm,  light  air  near  the  pipe,  and  it 
rises.  This  is  the  beginning  of  the  circulation  of 
the  atmosphere  of  the  room.  The  air  moves  inward 
along  the  floor  from  north  and  south  toward  the  hot 
steam  pipe;  the  air  near  the  pipe  moves  upward, 
carrying  heat  to  other  parts  of  the  room.  This 
process  of  carrying  heat  by  currents  of  air  is  called 
convection.  The  air  then  moves  outward  to  the 
north  and  south  along  the  upper  part  of  the  room, 
and  downward  in  the  north  and  south  parts  of  the 
room,  to  move  inward  again  along  the  lower  part  of 
the  room.  Some  air  passes  out  through  the  north 
and  south  windows  which  are  partly  opened,  accord- 


8 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


ing  to  our  supposition,  and  some  air  passes  in 
through  the  windows. 

Get  the  above  conditions  clearly  in  mind  so  that 
you  readily  see  in  imagination  the  air  movements 
described.  Picture  in  your  mind  the  circulation  of 
air  in  the  north  half  of  the  room,  and  in  the  south 
half  of  the  room. 

Circulation  of  the  Air  on  the  Earth  Without 
Eotation.  If  the  earth  did  not  rotate,  winds  would 
move  along  north-south  lines  as  the  air  moved  in 
the  school  room  heated  by  a steam  pipe.  Let  us 
apply  the  illustration  of  the  school  room  to  the 
earth’s  surface.  A warm  belt  of  air  several  hundred 
miles  wide  extends  east-west  around  the  earth  near 
the  equator.  This  belt  corresponds  to  the  warm, 
rising  air  near  the  steam  pipe.  It  is  called  the  belt 
of  equatorial  calms,  or  the  doldrums. 

The  cooler,  heavier  air  on  the  north  and  south 
sides  of  the  doldrums  moves  towards  the  doldrums 
as  the  air  moves  along  the  floor  of  the  school  room 
towards  the  steam  pipe.  These  are  the  trade  winds. 

As  the  air  of  the  doldrums  rises,  it  flows  off  to 
the  north  and  sonth  as  the  air  moves  outward  along 
the  upper  part  of  the  school  room.  These  are  the 
antitrade  winds.  The  name  means  against  the 
trades. 

Between  30  and  35  degrees  north  and  south  lati- 
tudes much  of  the  air  of  the  antitrades  settles  to 
the  earth.  This  downward  moving  air  produces 
calms,  which  are  called  the  horse  latitudes.  They 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  9 


correspond  to  the  downward  moving  air  in  the  north 
and  south  parts  of.  the  school  room. 

Some  of  the  downward  moying  air  of  the  horse 
latitudes  turns  toward  the  equator  and  supplies  the 
trades.  Some  moves  on  toward  the  poles.  These 
winds  moving  from  the  horse  latitudes  towards  the 
poles  are  the  prevailing  westerlies,  but  if  the  earth 
were  not  in  rotation  they  would  move  along  north- 
south  lines.  They  correspond,  in  some  measure,  to 
the  air  which  passed  through  the  windows  at  the 
north  and  south  ends  of  the  school  room. 

The  Naming  of  Winds.  It  is  important  to  be 
able  to  name  winds  accurately  and  quickly,  to  tell 
wind  directions  by  weather  vane,  or  other  means, 
and  to  represent  winds  on  charts  and  maps. 

Winds  are  always  named  by  the  direction  from 
which  they  blow.  Thus  a wind  moving  from  the 
south  toward  the  north  is  a south  wind,  from  the 
northeast  to  the  southwest  a northeast  wind.  The 
arrow  of  the  weather  vane  points  against  the  wind 
and  not  with  the  wind.  See  if  you  can  tell  why. 
When  the  weather  vane  points  west,  we  have  a west 
wind,  because  the  wind  is  blowing  from  the  west. 

Winds  are  represented  on  charts  and  maps  by 
means  of  arrows.  The  arrows  are  drawn  as  if  flying 
with  the  wind.  An  arrow  on  a chart  or  map  pointing 
to  the  east  represents  a west  wind.  Name  the  wind 
when  the  arrow  of  the  weather  vane  points  north- 
west. Represent  the  same  wind  by  an  arrow  on 
the  blackboard.  A flag  is  floating  northeast  from 
the  flagstaff.  Name  the  wind.  Represent  it  by  an 


10 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


arrow.  Which  direction  would  the  weather  vane 
point  for  this  same  wind!  Answer  the  same  points 
when  you  see  smoke  from  a chimney  floating  away 
to  the  south.  Are  you  sure  that  you  can  name  winds 
accurately  and  quickly,  and  can  you  represent  them 
correctly  on  a chart  or  map? 

Circulation  of  the  Air  on  a Rotating  Earth. 
If  the  earth  did  not  rotate,  all  winds  in  the  general 
circulation  of  the  atmosphere  would  be  either  north 
winds  or  south  winds.  Our  earth  is  a sphere  8,000 
miles  in  diameter,  25,000  miles  in  circumference, 
rotating  from  west  to  east  once  in  24  hours.  The 
reason  for  the  change  of  wind  direction  because  of 
the  earth’s  rotation  is  too  difficult  to  he  understood 
by  boys  and  girls,  hut  they  can  learn  to  what  extent 
the  winds  are  changed  by  the  earth’s  rotation. 

Memorize  the  following  law  of  winds:  Because 
of  the  earth’s  daily  rotation  from  west  to  east , winds 
in  the  northern  hemisphere  are  turned , or  deflected, 
to  the  right  hand;  and  winds  in  the  southern  hemi- 
sphere are  turned,  or  defected,  to  the  left  hand. 

Suppose  you  were  to  start  at  the  north  horse 
latitudes,  30  degrees  north  latitude,  and  go  toward 
the  doldrums,  turning  somewhat  to  the  right  as  you 
go.  In  what  direction  would  you  he  going?  You 
would  be  traveling  from  what  direction?  A wind 
following  the  same  line  would  receive  what  name? 
This  is  the  region  of  the  northeast  trade  winds. 

Suppose  you  were  to  start  at  the  south  horse  lati- 
tudes, 30  degrees  south  latitude,  and  go  toward  the 
doldrums,  turning  somewhat  to  the  left  as  you  go. 


GENERAL  CIRCULATION  OP  THE  ATMOSPHERE  11 


In  wliat  direction  would  you  be  going?  You  would  be 
traveling  from  wbat  direction?  A wind  following 
the  same  line  would  receive  wbat  name?  This  is  the 
region  of  the  southeast  trade  winds. 

The  air  which  rises  at  the  doldrums  spreads  north 
and  south  over  the  trade  winds  several  miles  above 
the  surface  of  the  earth,  and  moves  from  the  dol- 
drums toward  the  poles.  In  the  northern  hemi- 
sphere these  winds  move  northward  hut  are  deflected 
to  the  right  by  the  earth’s  rotation,  and  thus  become 
the  southwest  antitrades.  In  the  southern  hemi- 
sphere they  move  southward  but  are  deflected  to  the 
left  by  the  earth’s  rotation,  and  thus  become  the 
northwest  antitrades. 

Between  30  and  35  degrees  north  latitude,  and 
between  30  and  35  degrees  south  latitude  the  air 
of  the  antitrades  settles  downward  in  the  horse 
latitudes.  Some  of  this  downward  moving  air 
turns  hack  toward  the  equator  and  supplies  the 
northeast  trades  and  the  southeast  trades.  Some 
continues  toward  the  poles  in  the  same  general  di- 
rection as  the  antitrades.  These  winds  are  the 
prevailing  westerlies.  Since  the  westerlies  are  sur- 
face winds  moving  in  the  same  direction  as  the 
antitrades,  the  ivesterlies  of  the  northern  hemisphere 
are  southwest  winds,  and  the  westerlies  of  the  south- 
ern hemisphere  are  northwest  winds. 

The  law  of  winds  given  above  may  be  stated  in 
other  words  as  follows:  Because  of  the  earth’s 
daily  rotation  from  west  to  east:  winds  moving 
equatorward  are  turned,  or  deflected,  to  the  west; 


12 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


and  winds  moving  poleward  are  turned,  or  deflected, 
to  the  east. 

The  Wind  Belts  of  the  Earth  and  Their  An- 
nual Movement.  One  ray  of  the  sun  meets  the 


Figure  1.  WIND  BELTS  OF  THE  EARTH  IN  AVERAGE 
POSITION. 

From  Figure  1 learn  the  names  of  the  nine  wind  belts  of  the 
earth.  Give  the  name,  latitude  and  direction  of  air  movement  in  each 
of  the  nine  wind  belts.  If  you  learn  these  facts  first  about  the  dol- 
drums and  the  horse  latitudes,  you  can  learn  the  latitudes  of  the  other 
wind  belts  more  easily.  Two  of  the  nine  wind  belts  do  not  touch 
the  surface  of  the  earth.  Which  are  they?  How  are  they  represented? 


curved  surface  of  the  earth  so  as  to  make  a right 
angle  with  the  earth’s  surface  at  that  point.  This 
is  the  vertical  ray  of  the  sun.  All  other  rays  are 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  13 


oblique  rays.  If  the  vertical  ray  of  the  sun  were 
always  on  the  equator  the  wind  belts  of  the  earth 
would  remain  in  the  same  position  throughout  the 
year.  But  the  vertical  ray  of  the  sun  moves,  or 
migrates,  northward  to  23%  degrees  north  latitude 
on  June  21,  and  southward  to  23%  degrees  south 
latitude  on  December  21.  When  the  vertical  ray  is 


No™ 11  b j t t-. dlfc- 

Figure  2.  VERTICAL  SECTION  OF  WIND  BELTS  IN 
AVERAGE  POSITION. 

Turn  the  page  so  that  “North”  in  the  figure  is  actually  north. 
Compare  figure  2 with  figure  1.  Imagine  yourself  looking  at  a section 
of  the  air,  as  shown  in  the  figure,  extending  upward  ten  or  twelve 
miles  above  the  earth’s  surface,  and  from  pole  to  pole.  In  this  figure 
point  out  and  nam£  the  nine  wind  belts  and  give  latitude  and  direc- 
tion of  air  movement  in  each  as  in  figure  1. 

The  arrows  pointing  equatorward  in  the  middle  of  the  westerlies 
do  not  represent  a distinct  wind  belt.  They  simply  indicate  that  the 
air  which  has  been  carried  poleward  by  the  westerlies  must  return 
equatorward.  Just  how  this  is  done  is  not  fully  known. 


north  of  the  equator,  the  northern  hemisphere  has 
longer  days  and  steeper  rays  than  the  southern  hemi- 
sphere, and  so  receives most  of  the  sun’s  heat. 
Make  a similar  statement  for  the  southern  hemi- 
sphere when  the  vertical  ray  is  north  of  the  equator. 
Make  similar  statements  for  both  hemispheres  when 
the  vertical  ray  is  south  of  the  equator. 

The  doldrum  belt  moves  north  and  south,  but  not 
so  far,  nor  so  rapidly  as  the  vertical  ray  of  the  sun. 
The  doldrums  move  farther  from  the  equator  over 


14 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


land  than  over  the  water.  Wherever  the  doldrums 
pass  there  is  heavy  rainfall.  The  amount  of  their 
migration  to  the  north  and  the  south  of  the  equator 
on  land  is  best  determined  by  the  distance  north 


Figure  3.  WIND  BELTS  FOR  JULY— NORTHERN 
SUMMER,  SOUTHERN  WINTER. 

Compare  figure  3 with  figure  1.  Give  the  names,  latitude  and 
direction  of  air  movement  in  the  nine  wind  belts  for  July.  Give  first 
the  doldrums  and  horse  latitudes. 


and  south  of  the  equator  that  we  find  considerable 
rainfall  due  to  this  annual  migration  of  the  dol- 
drums. 

Your  school  geography  probably  contains  a good 
rainfall  map  of  the  world  and  of  each  of  the  conti- 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  15 


nents.  Find  these  maps  and  make  frequent  use  of 
them  as  you  study  geography.  In  this  pamphlet 
reference  will  be  made  to  maps  of  Longmans’  New 
School  Atlas,  price  $1.50.  This  Atlas  should  be  in 


Figure  4.  WIND  BELTS  IN  JANUARY— NORTHERN 
WINTER,  SOUTHERN  SUMMER. 

Compare  figure  4 with  figures  1 and  3.  Give  the  names,  latitude 
and  direction  of  air  movement  in  the  nine  wind  belts  for  January. 

Make  a table  of  four  columns.  In  column  1,  place  names  of  wind 
belts;  in  column  2,  the  average  latitude;  in  column  3,  latitude  for 
July;  in  column  4,  latitude  for  January. 

every  school.  Obtain  it  through  your  local  book 
dealer.  By  examining  the  Bainfall  Map  of  the 
world  in  your  text  book  or  in  Longmans’  Atlas  we 
find  that  that  part  of  Africa  lying  between  20  de- 


16 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


grees  north  latitude  and  20  degrees  south  latitude 
receives  much  more  rainfall  than  the  regions  farther 
north  or  south.  The  same  is  true  for  the  West 
Indies  and  for  those  parts  of  North  America  and 
South  America  lying  between  and  somewhat  beyond 
the  same  parallels,  but  the  influence  of  the  doldrums 
is  not  so  clearly  marked  as  in  Africa.  This  fact 
of  heavy  rainfall  is  shown  in  the  East  Indies  and  in 
those  portions  of  Asia,  and  Australia  lying  between, 
and  in  some  cases  beyond,  the  same  parallels. 

It  will  be  helpful  in  our  study  of  wind  belts  and 
their  influence  on  rainfall  to  consider  that  the  dol- 
drums migrate  northward  so  that  the  northern  edge 
reaches  about  20  degrees  north  latitude,  and  south- 
ward so  that  the  southern  edge  reaches  about  20 
degrees  south  latitude.  The  width  of  the  doldrums 
differs  in  different  places  and  in  different  seasons. 
It  will  be  helpful  to  consider  it  as  having  a width 
of  about  10  degrees  of  latitude  or  about  700  miles. 
The  average  position  of  the  doldrums  may  then  be 
considered  from  5 degrees  north  latitude  to  5 de- 
grees south  latitude;  their  most  northern  position 
in  northern  summer  (southern  winter)  from  10  de- 
grees north  latitude  to  20  degrees  north  latitude, 
and  their  most  southern  position  in  northern  win- 
ter (southern  summer)  from  10  degrees  south  lati- 
tude to  20  degrees  south  latitude. 

The  doldrums  form  the  center  of  the  entire  sys- 
tem of  wind  belts.  As  the  doldrums  migrate  north 
and  south,  all  other  wind  belts  migrate  in  the  same 
direction  as  the  doldrums,  but  not  so  far.  The 


GENERAL  CIRCULATION  OP  THE  ATMOSPHERE  17 


average  latitude  of  the  horse  latitudes  may  be  con- 
sidered 30  to  35  degrees  both  north  and  south  of 
the  equator.  In  the  northward  migration  the  north 
horse  latitudes  occupy  35  to  40  degrees  north  lati- 
tude and  the  south  horse  latitudes  25  to  30  degrees 
south  latitude.  In  the  southward  migration  the 
north  horse  latitudes  occupy  25  to  30  degrees  north 
latitude  and  the  south  horse  latitudes  occupy  35  to 
40  degrees  south  latitude.  These  latitudes  give  us 
only  a general  notion  of  the  shifting  or  migration 
of  the  wind  belts.  The  boundaries  of  the  wind  belts 
are  not  sharply  defined,  and  these  boundaries  do  not 
follow  exactly  lines  of  latitude.  The  two  regions 
between  the  doldrums  and  horse  latitudes  are  always 
occupied  by  the  trades  as  surface  winds  and  by  the 
antitrades  as  upper  winds.  The  two  regions  be- 
tween the  horse  latitudes  and  the  polar  areas  are 
always  occupied  by  the  prevailing  westerlies.  Learn 
the  general  location  of  the  doldrums  and  horse  lati- 
tudes and  you  then  know  the  location  of  all  other 
wind  belts. 

Make  a study  of  Figs.  1,  2,  3,  and  4.  In  each 
figure  name  and  locate  by  latitude  the  nine  wind 
belts  described  above,  and  give  the  direction  of  air 
movement  in  each.  Give  your  description  in  com- 
plete correct  sentences.  Give  latitude  fully.  Al- 
ways using  the  words  “degrees”  after  the  number, 
and  state  whether  it  is  “north  latitude”  or  “south 
latitude.”  The  latitude  nearer  the  equator  should 
be  given  first. 

A Map  Exercise.  1.  On  an  outline  map  of  the 


18 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


world  trace  with  pencil  the  equator.  Name  the  con- 
tinents, oceans,  and  the  groups  of  islands  crossed. 
Note  what  part  of  each  continent  is  crossed  by  the 
equator.  Name  the  countries  of  South  America 
crossed  by  the  equator;  of  Africa;  three  or  more 
islands.  To  find  these  names  turn  to  the  political 
maps  of  the  different  continents  in  your  school 
geography. 

2.  On  the  same  map  draw  20  degrees  north 
latitude  and  20  degrees  south  latitude.  From  maps 
in  your  geography  name  the  continents,  oceans,  other 
water  bodies,  islands,  and  the  countries  crossed  by 
each  parallel.  Parts  of  five  continents  lie  between 
these  parallels.  Write  the  names  of  these  five  con- 
tinents and  under  the  name  of  each  continent  write 
the  names  of  the  countries  which  lie  wholly  or  partly 
between  these  two  parallels.  These  are  the  coun- 
tries of  the  world  which  are  influenced  by  the  dol- 
drums in  their  annual  migration.  During  a part  of 
the  year  these  same  regions  are  influenced  by  the 
trade  winds. 

3.  On  the  same  map  draw  30  degrees  north  lati- 
tude and  30  degrees  south  latitude.  Name  the  coun- 
tries crossed  by  each.  The  horse  latitudes  and  the 
trade  winds  usually  bring  little  rainfall.  The 
countries  between  20  degrees  and  30  degrees  of  lati- 
tude both  north  and  south  of  the  equator  lie  almost 
wholly  in  the  trade  winds  and  horse  latitudes 
throughout  the  entire  year.  Therefore,  they  have 
little  rainfall  as  a rule,  and  contain  extensive  deserts. 

Examine  a vegetation  map  in  your  geography  or 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  19 


in  Longmans’  Atlas  and  note  the  regions  of  desert 
land  between  20  degrees  and  30  degrees  latitude  in 
both  hemispheres.  Write  a list  of  countries  between 
these  latitudes  in  the  northern  hemisphere,  another 
list  for  the  southern  hemisphere.  If  your  school  is 
supplied  with  large  wall  maps  of  the  continents, 
study  them  and  compare  them  with  the  maps  in  your 
geography. 

4.  The  countries  between  the  latitude  of  40  de- 
grees and  the  poles  are  in  the  prevailing  westerlies 
for  all  of  the  year.  Countries  between  30  degrees 
and  40  degrees  latitude  are  influenced  for  a part  of 
the  year  (winter)  by  the  westerlies,  and  for  the  rest 
of  the  year  (summer)  by  the  horse  latitudes  and 
trades.  Each  of  the  six  continents  contains  regions 
influenced  by  the  westerlies.  Write  the  names  of 
the  six  continents,  and  under  the  name  of  each  con- 
tinent write  the  names  of  the  countries  which  lie 
between  30  degrees  and  the  poles.  These  countries 
are  in  the  westerly  winds  for  all  or  a part  of  the 
year.  In  southern  Europe  and  western  Asia  the 
influence  of  the  dry  horse  latitudes  is  carried  some- 
what farther  north  than  40  degrees  north  latitude 
in  northern  summer,  probably  as  far  as  43  degrees. 

Test  your  imagination  to  see  whether  you  can 
think  of  the  earth  as  a whole,  spherical  in  shape, 
8,000  miles  in  diameter,  25,000  miles  in  circumfer- 
ence, surrounded  by  an  atmosphere  100  miles  or 
more  in  thickness.  One-half  of  the  atmosphere,  by 
weight,  is  within  3.6  miles,  and  nearly  all  of  it  is 


20 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


within  10  miles,  of  the  earth’s  surface.  The  higher 
atmosphere  is  very  rare. 

Think  of  the  wind  belts  we  have  named  in  their 
average  latitudes  and  the  air  moving  up  in  the  dol- 
drums, down  in  the  horse  latitudes,  equatorward  in 
the  trades,  and  poleward  in  the  antitrades  and  west- 
erlies. Think  of  the  vertical  ray  of  the  sun  moving 
northward  at  the  rate  of  about  18  miles  per  day,  the 
doldrums  migrating  only  about  half  as  fast,  and  the 
horse  latitudes  shifting  still  more  slowly.  Then 
think  of  the  reverse  movement  to  the  south.  Think 
of  all  these  things  as  they  really  are  on  the  earth. 
Learn  your  home  latitude,  and  think  how  far  each 
wind  belt  is  away  from  you  in  degrees  of  latitude, 
and  in  miles.  One  degree  of  latitude  should  always 
he  counted  70  miles  in  computing  distances  in  geog- 
raphy. Degrees  of  longitude  differ  in  length  from 
70  miles  at  the  equator  to  zero  at  the  poles.  One 
degree  of  longitude  at  30  degrees  latitude  is  60 
miles;  at  40  degrees  53  miles;  at  50  degrees  45 
miles;  at  60  degrees  35  miles;  at  70  degrees  24 
miles;  and  at  80  degrees  12  miles. 

Monsoons.  The  foregoing  description  of  wind 
belts  has  not  taken  into  account  the  influence  of 
large  areas  of  land  and  water  in  modifying  the 
winds.  In  India  and  elsewhere  we  have  winds 
known  as  monsoons.  India  furnishes  the  best  ex- 
ample of  monsoons  in  the  world.  Monsoons  are 
seasonal  winds,  that  is,  they  change  their  direction 
in  summer  and  winter.  They  blow  from  the  ocean 
toward  the  land  in  summer,  these  are  the  summer 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  21 


monsoons;  and  from  the  land  toward  the  ocean  in  the 
winter,  these  are  the  winter  monsoons. 

Monsoons  are  caused  by  the  difference  in  tem- 
perature between  the  ocean  and  large  land  areas  in 
summer  and  winter.  With  the  long  days  and  steep 
rays  of  northern  summer  the  great  land  mass  of 
Central  Asia  becomes  much  warmer  than  the  water 
of  the  Indian  Ocean,  because  land  heats  more  rap- 
idly than  water.  The  warm  air  over  the  land  ex- 
pands and  grows  lighter.  The  cooler,  heavier  air 
over  the  ocean  blows  strongly  toward  the  land,  car- 
rying great  quantities  of  water  vapor  over  India, 
producing  abundant  rainfall. 

With  the  shorter  days  and  more  slanting  rays 
of  northern  winter  the  great  land  mass  of  Asia  be- 
comes much  colder  than  the  water  of  the  Indian 
Ocean,  because  land  cools  more  rapidly  than  water. 
The  heavier,  colder  air  of  the  land  then  blows  toward 
the  ocean.  This  winter  monsoon  is  a cool,  dry  wind. 
Some  school  geographies  have  maps  showing  the 
monsoons  of  India  in  opposite  seasons.  Such  maps 
should  be  studied  and  fully  understood. 

Monsoons  also  occur  in  southeastern  Asia,  in 
Australia,  on  the  west  coast  of  Africa  north  of  the 
equator,  in  Spain,  and  to  some  extent  in  other 
regions. 

Cyclonic  Storms  of  the  Prevailing  Westerlies. 
The  prevailing  movement  of  the  westerlies  from  the 
southwest  in  the  northern  hemisphere  and  from  the 
northwest  in  the  southern  hemisphere  is  interrupted 
by  the  passage  of  cyclonic  storms.  The  cyclone  is 


22 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


a storm  of  vast  extent,  in  which  the  winds  blow 
spirally  about  a calm  center.  The  winds  blow  from 
all  directions  toward  the  center,  which  is  a region 
of  lighter  air  than  that  surrounding  it.  The  move- 
ment of  these  cyclonic  storms  from  west  to  east 
across  the  continent  brings  to  us  the  ordinary 
changes  of  weather  from  day  to  day. 

Since  the  ivinds  blow  from  all  directions,  they 
may  carry  moisture  from  any  direction  in  which  a 
large  body  of  warm  water  is  found.  Thus  the 
cyclonic  storms  of  Europe  carry  moisture  from  the 
Atlantic  Ocean  which  lies  on  the  west,  and  distribute 
it  far  inland  over  the  great  central  plain  of  Europe. 
The  cyclonic  storms  of  North  America  bring  rain 
to  the  west  coast  by  westerly  winds  from  the  Pacific. 
The  mountains  are  so  close  to  the  west  coast  of 
North  America,  however,  that  abundant  rainfall  is 
found  only  along  a narrow  strip  of  our  western 
states,  Canada  and  Alaska.  Examine  rainfall  map 
of  North  America  and  United  States  in  Longmans’ 
Atlas,  maps  6 and  15,  or  in  your  geography. 

In  the  eastern  half  of  the  United  States  and 
Canada  the  west  winds  are  dry  winds  because  they 
blow  from  large  land  areas  to  the  west.  Yet,  the 
eastern  half  of  both  countries  is  much  better  watered 
than  the  western  half.  Examine  a rainfall  map  of 
North  America  and  the  United  States.  This  is  be- 
cause the  cyclonic  storms  are  made  up  of  winds 
blowing  from  all  directions.  The  moist,  rain-bear- 
ing winds  come  from  the  east,  southeast,  and  south, 
bringing  abundant  moisture  from  the  Atlantic 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  23 


Ocean  and  the  Gulf  of  Mexico,  to  fall  as  rain  over 
the  United  States  and  Canada  as  far  west  as  the 
Rocky  Mountains.  The  amount  of  rainfall  decreases 
gradually  from  the  Atlantic  and  Gulf  of  Mexico  to 
the  northwest,  until  we  reach  the  desert  regions 
beyond  the  mountains.  See  rainfall  map. 

If  it  were  not  for  the  cyclonic  storms  of  the  west- 
erlies, with  their  ability  to  carry  moisture  from  the 
east  and  south,  that  part  of  the  United  States  and 
Canada  lying  between  the  Rocky  Mountains  and 
the  Atlantic  Ocean  would  he  one  vast  desert,  as  dry 
and  barren  as  the  Sahara. 

Tornado  is  the  name  applied  to  a violent  whirl- 
ing narrow  storm  of  the  Mississippi  Valley.  Tor- 
nadoes occur  in  the  southeast  quarter  of  a cyclone. 
The  tornado  is  often  called  a cyclone,  hut  incor- 
rectly. 

In  the  southern  hemisphere  the  cyclonic  storms 
of  the  westerlies  influence  those  parts  of  South 
America,  Africa,  and  Australia  lying  south  of  the 
vicinity  of  30  degrees  south  latitude.  Examine 
rainfall  maps  of  these  continents. 

Tropical  Cyclones.  These  are  large,  violent, 
and  destructive  storms  starting  in  the  doldrums 
over  the  oceans  at  certain  times  of  the  year.  They 
occur  in  the  North  Atlantic,  occasionally  doing 
great  destruction  in  the  West  Indies  and  along  our 
Gulf  and  Atlantic  coasts.  They  also  occur  in  the 
Indian  and  Pacific  Oceans,  causing  damage  in  the 
East  Indies  and  along  the  coasts  of  India  and 
China.  Hurricane  is  the  name  given  to  the  tropical 


24 


IMPORTANT  TOPICS  IN  GEOGRAPHY 


cyclones  of  the  North  Atlantic;  they  are  called 
typhoons  in  the  North  Pacific. 

Maps.  The  outline  maps  of  the  world  necessary 
for  the  map  exercise  given  on  p.  17  may  be  obtained 
from  McKnight  & McKnight,  Normal,  Illinois,  for  lc 
each  if  taken  in  lots  of  10  or  more.  Each  pupil 
should  have  at  least  two  outline  maps  for  the  exer- 
cise. On  request,  McKnight  & McKnight  will  send 
a pamphlet,  very  helpful  to  teachers,  on  “Outline 
Maps  and  Their  Use.” 

Pictures.  The  following  pictures  from  the  ‘ ‘ 600 
set”  of  lantern  slides  and  stereographs  of  the  Key- 
stone View  Company,  Meadville,  Pennsylvania,  are 
selected  for  the  purpose  of  showing  characteristic 
scenes  in  the  different  wind  belts  of  the  earth. 
These  pictures  will  aid  greatly  in  giving  concrete- 
ness and  reality  to  the  study  of  a somewhat  abstract 
problem  in  geography.  Each  picture  should  be 
studied  with  reference  to  the  wind  belt  in  which  it 
occurs.  Each  view  should  become  familiar  to  the 
pupils  as  to  title,  country,  approximate  latitude,  and 
life  forms,  whether  plant,  animal,  or  human  life. 
Pupils  should  be  taught  to  study  the  splendid  cata- 
log of  the  “600  set”  of  Keystone  Views,  and  learn 
to  make  individual  use  of  the  stereographs  in  geog- 
raphy and  other  studies. 

The  numbers  are  the  serial  numbers  in  the  list 
of  600,  and  are  instantly  available  in  any  school 
provided  with  the  600  set  of  stereographs  or  lan- 
tern slides.  These  pictures  may  be  examined  early 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  25 


in  the  study  of  this  pamphlet,  during  its  study,  or 
at  the  close,  as  a review  of  the  work. 

Doldrums.  232,  237,  242,  243,  249,  304,  307,  310, 
329,  333. 

Trade  Wind  Eegious  at  some  distance  from  the 
sea.  288,  292,  294,  576,  577,  578,  579,  584,  593,  596. 

Trade  Wind  Coasts  and  Islands.  233,  234,  235, 
301,  314,  315,  325,  327. 

Monsoon  Regions.  492,  493,  497,  500. 

Horse  Latitudes.  196,  197,  199,  200,  201,  476, 
482,  486,  488. 

Westerlies,  west  coast.  214,  215,  216.  217,  218, 
219,  221,  340,  341. 

Westerlies,  interior,  or  toward  east  coast.  17, 
41,  43,  44,  108,  132,  151,  152,  153,  154,  208,  220,  223, 
224,  225,  255,  258,  342,  345,  359,  416,  431,  433,  519,  530. 


TOPICAL  ANALYSIS 

GENERAL  CIRCULATION  OF  THE  ATMOSPHERE 

I.  Introduction. 

II.  Some  facts  to  be  remembered. 

1.  Air  has  weight. 

2.  Air  when  warmed,  expands;  when 

cooled,  contracts. 

3.  Warm  air  is  lighter  than  cold  air. 

4.  Warm  air  can  hold  more  water  vapor, 

or  moisture,  than  cold  air. 

5.  Moist  air  is  lighter  than  dry  air. 


26 


IMPOBTANT  TOPICS  IN  GEOGBAPHY 


III.  Circulation  of  air  on  a small  scale. 

1.  Around  a lighted  lamp. 

2.  Smoke  from  the  house  chimney. 

3.  The  bonfire. 

4.  The  hot  stove. 

5.  In  school  room  heated  by  steam  pipe. 

IV.  Circulation  of  the  air  on  the  earth  without 

rotation. 

1.  Equatorial  calms,  or  doldrums. 

2.  Trade  winds. 

3.  Antitrade  winds. 

4.  Horse  latitudes. 

5.  Prevailing  westerlies. 

V.  The  Naming  of  Winds. 

VI.  Circulation  of  the  air  on  a rotating  earth. 

1.  The  equatorial  calms,  or  doldrums. 

2.  Northeast  trade  winds. 

3.  Southeast  trade  winds. 

4.  Southwest  antitrades. 

5.  Northwest  antitrades. 

6.  Horse  latitudes  of  the  northern  hemi- 

sphere. 

7.  Horse  latitudes  of  the  southern  hemi- 

sphere. 

8.  Westerlies  of  the  northern  hemisphere. 

9.  Westerlies  of  the  southern  hemisphere. 

VII.  The  wind  belts  of  the  earth  and  their  annual 
movement. 


GENERAL  CIRCULATION  OF  THE  ATMOSPHERE  27 


1.  Migration  of  the  sun’s  vertical  ray. 

2.  Migration  of  the  doldrum  belt. 

3.  Migration  of  the  horse  latitudes. 

4.  Average  location  of  wind  belts.  Figs.  1 

and  2. 

5.  Location  of  wind  belts  in  northern  sum- 

mer. Fig.  3. 

6.  Location  of  wind  belts  in  northern  win- 

ter. Fig.  4. 

"VTII.  A Map  Exercise. 

1.  The  relation  of  equator  to  continents 

and  countries. 

2.  Countries  between  20  degrees  north 

latitude  and  20  degrees  south  latitude. 

3.  Countries  between  20  degrees  and  30 

degrees  latitude  in  both  hemispheres. 

4.  Countries  between  30  degrees  and  the 

poles. 

IX.  Monsoons. 

X.  Cyclonic  Storms  of  the  prevailing  westerlies. 
1.  Tornado. 

XI.  Tropical  Cyclones. 

1.  Hurricanes. 

2.  Typhoons. 

XII.  Maps. 

XIII.  Pictures. 

Use  the  foregoing  Topical  Outline  for  Summary 
and  Eeview. 


Normal  School  Series  of 
Outline  Maps  and  Observation 
Blanks 


These  Maps  and  Blanks  have  been  prepared  under  the  direction  of 
Douglas  C.  Ridgley,  of  the  Department  of  Geography, 
of  the  Illinois  State  Normal  University 

Published  by  McKNIGHT  & McKNIGHT,  Normal , Illinois 


The  List  of  Maps  and  Blanks,  Thus  Far  Issued, 
Includes  the  Following: 


1.  Illinois. 

2.  United  States. 

3.  United  States  (without 

drainage.) 

4.  North  America. 

5.  North  America  (without 

drainage.) 

6.  South  America. 

7.  Europe. 

8.  Asia. 

9.  Africa. 

10.  Australia. 

11.  The  World. 

12.  Normal  University  Campus 

(Topographic  Map.) 

13.  Eurasia. 

101.  Southern  United  States  and 

Mexico. 

102.  New  England  and  New 

Netherlands. 


14.  Missouri. 

15.  Iowa. 

16.  Wisconsin. 

17.  Indiana. 

51.  Ruled  Blank  for  Recording 

Observations  of  the  Sun. 

52.  Ruled  Blank  for  Recording 

Observations  of  the  Moon. 

53.  Ruled  Blank  for  Recording 

Weather  Observations 
without  instruments. 

54.  Ruled  Blank  for  Recording 

Weather  Observations 
without  instruments. 

55.  Ruled  Blank  for  Recording 
Observations  of  Planets 
and  Stars. 


103.  Eastern  United  States  and 

Canada. 

104.  NortheasternUnited States. 

105.  Southeastern  United  States. 


History  Maps 


New  Maps  are  being  issued  as  the  demand  arises 


PRICES 

Ten  or  more  maps  or  Blanks  assorted,  1 cent  each;  per  hundred,  80  cents;  per 
thousand,  $6.50,  except  numbers  12  and  101,  which  are  double  size  and  count  each 
as  two  maps.  These  prices  are  postpaid,  to  any  address  in  the  United  States. 


McKNIGHT  & McKNIGHT,  Publishers 

NORMAL,  ILLINOIS 


Normal  School  Series  of 
Outline  Maps  and  Observation 
Blanks  AZasT 

The  maps  and  blanks,  in  sets,  bound  in  strong  manila  covers, 
arranged  with  special  reference  to  the  Illinois  State  Course  of  Study 
in  Geography  and  History.  Price  per  set  made  on  a basis  of  1 cent 


for  each  map  or  blank.  pHce  Per  Sef 

Fourth  Year  Geography  ....  10c 

Fifth  Year  Geography  ....  25c 

Seventh  Year  Geography  ....  25c 

Eighth  Year  Geography  ....  35c 

Physical  Geography  .....  35c 

Commercial  Geography  ....  35c 

Sixth  Year  History  . . . . . 15c 

Seventh  Year  History  .....  20c 

Eighth  Year  History  .....  20c 

Map-Nets  . . . . . . 10c 

The  following  sets  have  been  arranged  for  schools  having  a 
Course  of  Study  of  their  own: 

Observation  Blanks  .....  10c 

Elementary  Geography  ....  25c 

Trip  Around  the  World  ....  15c 

Outline  Maps  of  North  America  . . . 20c 

Outline  Maps  of  South  America  . . . 10c 

Outline  Maps  of  Europe  ....  15c 

Outline  Maps  of  Asia  .....  10c 

Outline  Maps  of  Africa  ....  10c 

Outline  Maps  of  Australia  ....  10c 

Map-Nets  of  the  World,  with  notes  . . . 10c 


Sets  of  Maps,  combining  any  numbers  of  the  above  list,  will  be 
put  up  specially  on  request,  providing  there  are  not  less  than  ten 
maps  in  a set. 

In  ordering  a number  of  sets  in  which  the  aggregate  number  of 
maps  is  100  or  1000,  the  price  will  be  the  same  as  for  the  single  maps 
or  blanks,  notwithstanding  they  are  bound  in  substantial  covers. 

For  further  information  address 

McKNIGHT  & McKNIGHT,  Publishers 

NORMAL,  ILLINOIS 


List  of 

Supplementary  Readers  and 
Books  for  Teachers 


Selected  Readings  for  First  and  Second  Grades 

Rimes  and  Stories  .......  35c 

Classic  Stories  for  the  Little  Ones 

Teachers’  edition  ......  40c 

Pupils’  edition  ......  35c 

Songs  of  the  Tree  Top  and  Meadow  ....  40c 

Stories  of  Indian  Children  .....  40c 

For  Primary  and  Intermediate  Grades 

The  Little  Cliff-Dwellers  .....  35c 

Robinson  Crusoe  for  Boys  and  Girls 

Teachers’  edition  ......  40c 

Pupils’  edition  ......  35c 

The  Story  of  Ulysses  ......  50c 

Wagner  Opera  Stories  ......  50c 

The  Lolami  Books  (2  vols.)  each  ....  50c 

Tales  of  Troy  .......  35c 

History  and  Nature  Stories  for  Intermediate  and 
Grammar  Grades 

The  Fly-Aways  and  Other  Seed  Travelers  . . . 60c 

Stories  of  Indian  Chiefs  ......  40c 

The  Story  of  Lincoln  ......  35c 

Pioneers  of  the  Revolution  .....  35c 

The  King  and  His  Wonderful  Castle  ....  35c 

Jack  and  Nell  in  Field  and  Forest  ....  50c 

Out  Door  Studies  in  Geography  (2  parts),  each  part  . . 60c 

Bound  together  . . . . . $1.00 

The  Story  of  Our  English  Grandfathers,  introductory,  75c;  mail  1.00 


Books  for  Teachers 


Jean  Mitchell’s  School  ....  $1.00 
Glimpses  of  Child  Nature  ...  .50 

The  Point  of  View  of  Modern  Education  .60 
Suggestions  on  Teaching  Geography  . .50 

School  and  Home  Education,  per  year  . 1.25 

(A  Magazine  all  teachers  will  find  of  interest) 


For  the  High  School 


Lampe’s  Latin  Drill  Book  . . . $0.25 

Lampe’s  German  Drill  Book  . . . .25 

Music 

Elements  of  Music  and  Notation  . . .25 

By  F.  W.  Westhoff,  Director  of  Music,  Illinois  State  Normal  University 
Normal,  Illinois 


Dealers  and  Teachers  ordering 
a number  of  copies  at  one  time  will  be 
allowed  the  usual  trade 

discount 


For  further  information  address 

Mcknight  & Mcknight 

NORMAL:ILLINOIS 


3 0112  072839480 


Geographical  Pamphlet 
Series 


Dealing  with 
Important  Topics  in 
Geography 


General  Circulation  of  the  Atmosphere  . . . 15c 

*■  By  Douglas  C.  Ridgley 

Rainfall  of  the  Earth 15c 

By  Douglas  C.  Ridgley 

Vegetation  Zones  of  the  Earth 15c 

By  Douglas  C.  Ridgley 

Population  of  the  Earth  (now  being  prepared)  . . 15c 

By  Douglas  C.  Ridgley 

A Trip  Around  the  World  on  the  Fortieth  Parallel  of 

North  Latitude 10c 

By  Douglas  C.  Ridgley 

Normal  School  Series  of  Outline  Maps  and  Observation 
Blanks,  each  . lc 

(These  are  also  put  up  in  sets  in  strong  manila  covers,  each 
set  in  an  envelope,  for  Geography  and  History  work  in  the 
grades  and  high  school.) 


McKnight  & McKnight 

Publishers 

NORMAL,  ILLINOIS 


